Field
The present invention primarily relates to the use of specific herbicide combinations based on iodosulfuron or of a composition comprising said specific herbicide combinations for controlling harmful plants in teff (Eragrostis tef) plants. The present invention also relates to the use of specific herbicide combinations based on iodosulfuron or of a composition comprising said specific herbicide combinations as plant growth regulators for teff (Eragrostis tef) plants. Furthermore, the present invention relates to a corresponding method of controlling harmful plants in teff (Eragrostis tef) plants and to a corresponding method of regulating plant growth of teff (Eragrostis tef) plants.
Description of Related Art
Teff (Eragrostis tef), also called Williams lovegrass or taf, is an annual grass, a species of lovegrass native to the northern Ethiopian Highlands and Eritrean Highlands of the Horn of Africa.
Teff (Eragrostis tef) (hereinafter also referred to as “teff”) has an attractive nutrition profile, being high in dietary fiber and iron and providing protein and calcium. Teff is adapted to environments ranging from drought stress to waterlogged soil conditions.
Teff has been widely cultivated and used in the countries of Eritrea and Ethiopia, and accounts for about a quarter of total cereal production in Ethiopia. In a study in Ethiopia, farmers indicated a preference among consumers for white teff over darker colored varieties.
Teff is gaining popularity in the western United States as an alternative forage crop, in rotation with a legume such as alfalfa, because it uses C4 photosynthesis.
Teff is an important food grain in Ethiopia and Eritrea, and less so in India and Australia. It is now raised in the U.S., in Idaho in particular, with experimental plots in Kansas. In addition to people from traditional teff-consuming countries, customers include those on gluten-restricted diets. Teff has a high concentration of different nutrients, very high calcium content, and significant levels of the minerals. Teff is high in protein and considered to have an excellent amino acid composition, including all 8 essential amino acids for humans. Teff is also valued for its fine straw, and it has been used to produce gluten free beer.
Teff is a warm-season C4 annual grass crop grown for forage and food grain that has recently increased in production in parts of the United States. Hay from teff is well suited for livestock.
Teff has long been grown for hay and grain in Ethiopia where it is a major food crop.
Weed control has been identified as the most limiting factor in attaining better teff grain yield.
Lower yields are to a large extent due to effects of weed competition or to uncontrolled or unsufficiently controlled weed growth. Hoe-weeding still is a common practice among teff farmers in many regions.
In Tropical Pest Management 1983, 29, 333-338 eleven herbicides were tested in pot experiments for the control of Phalaris paradoxa and Setaria pallidefusca in teff. Some of the herbicides used only gave partial control of these two weeds and/or did not show selectivity. Chlorsulfuron applied pre-emergence was safe on teff and controlled both weed species. Diclofop-methyl, only when applied pre-emergence with a safener, was tolerated by teff, and controlled both weeds. Other herbicides like alachlor, pendimethalin or metoxuron, with or without the safener, failed to show selectivity.
The authors of the North Central Weed Science Society Proccedings 2006, 61:40 report on the sensitivity of teff (Eragrostis tef) to various herbicides. It is mentioned that field studies conducted Kansas showed that post-emergence applications of 2,4-D, dicamba, bromoxynil, carfentrazone, halosulfuron, and prosulfuron resulted in less than 5% injury on teff at 8 week after treatment, whereas mesotrione, sethoxydim, and glyphosate resulted in yield reductions of 30, 50, and 99%, respectively.
In the Crop and Soil Report 14 SR 10-08, p. 43-44 of the Oregon State University the authors summarized the results observed in preliminary field studies conducted in Oregon in 2009 regarding the tolerance of teff to several herbicides. For example, mesotrione treatments resulted in 100% injury to the teff when applied preemergence. Some of the postemergence treatments caused significant injury to teff. For example, pinoxaden caused 70% injury, mesotrione caused 63% injury, nicosulfuron caused 20% injury, and mesosulfuron caused 10% injury to teff when applied postemergence. The postemergence treatments that caused little or no teff injury were inter alia metribuzin, flucarbazone, clopyralid, fluroxypyr, pyraflufen, metsulfuron, chlorsulfuron, and tribenuron. However, some of these herbicide treatments did not control the weed species spectrum present in the field. The two treatments at the site that resulted in the highest levels of weed control, teff safety and teff yields were postemergence applications of metsulfuron and chlorsulfuron.
Weed Technology 2014, (28), 371-376 reports on the tolerance of teff to post-emergence herbicides, specifically 2,4-D amine, dimethylamine salt of dicamba, carfentrazone-ethyl and a mix of florasulam, fluoroxypyr and pryoxsulam.
WO 2013/127860 A1 discloses the use of agrochemical compositions comprising at least one herbicide and at least one fungicide in cereals.
In their application, herbicidal crop protection agents (herbicides) known to date for controlling harmful plants or unwanted vegetation in teff (Eragrostis tef) plants have some disadvantages, be it (a) that they have no or else insufficient herbicidal activity against specific harmful plants, (b) that the spectrum of harmful plants which can be controlled with the herbicides is not broad enough, and/or (c) that the selectivity of herbicides in and the compatibility with teff (Eragrostis tef) plants is too low, thereby causing unwanted damage and/or unwanted reduced harvest yields of teff (Eragrostis tef).
Overall, the herbicidal activity (above aspects (a) and (b)) and/or the selectivity/compatibility (above aspect (c)) of the herbicides used so far in teff (Eragrostis tef) plants still allows improvement.
For the reasons mentioned above, there still is a need for alternative, highly active herbicides or herbicidal compositions for the selective application for controlling harmful plants or unwanted vegetation in teff (Eragrostis tef) plants.